<div class="container" style="width: 400px; height: 400px">
    <form action="accionBorrar.php" method="post">
    <table class="table table-hover">
        <tr>
            <td>
                <label>Codigo:</label>
            </td>
            <td>
                <input type="text" id="txtID" name="txtID" value="<?php 
                if(isset($_GET['codigo'])){
                    echo $_GET['codigo'];
                }
                ?>"/>
            </td>
            
        </tr> 
        <tr>
            <td>
            </td>
            <td>
                <input type="submit" id="btnBorrar" name="txtBorrar" value="Borrar"/>
            </td>
            
        </tr>
    </table>
    
</form>
</div>